Filter media can be used to remove contamination in a variety of applications. In some cases, the filter media is formed of a web of fibers. The fiber web provides a porous structure that permits a fluid (e.g., a gas or a liquid) to flow through the filter media. Contaminant particles contained within the fluid may be trapped on the fibrous web. Depending on the application, the filter media may be designed to have different characteristics. Filter media characteristics, such as water repellency, pressure drop, surface area, and basis weight affect filter performance including filter efficiency and resistance to fluid flow through the filter. In general, higher filter efficiencies result in a higher resistance to fluid flow which leads to higher pressure drops for a given flow rate across the filter.
There is a need for filter media that have a desirable balance of properties including a high water repellency, a high efficiency, and a low resistance to fluid flow across the filter media.